BAD 
Now I have to use this to do presentation:
john@john-laptop:/etc/acpi$ cat videobtn.sh
#!/bin/sh
test -f /usr/share/acpi-support/key-constants || exit 0
. /usr/share/acpi-support/key-constants
acpi_fakekey $KEY_VIDEOOUT
CRT=/proc/acpi/video/VGA/CRT/state
LCD=/proc/acpi/video/VGA/LCD/state
if grep "state:.*0x0d" $CRT 1>/dev/null 2>&1
then
echo 0x80000001 > $CRT
# echo 0x80000001 > $LCD
else
echo 0x80000000 > $CRT
echo 0x80000001 > $LCD
fi
